Multiple-contact timer.



H S. LINCOLN.

MULTIPLE CONTACT TIMER.

APPLICATION FILED MAY 5,1908.

PatentedJune 22, W09.

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UNITED STATES PeTENT OFFICE.

EDWIN S. LINCOLN, OF BROO-KLINE, MASSACHUSETTS, ASSIGNOR T0 ELECTRICGOODS MAN- UFACTURING COMPANY, 'OF BOSTON, MASSACHUSETTS, A CORPORATIONOF MAINE.

MULTIPLE-CQNTACT TIMER.

Specification of Letters Patent.

Application filed May 5, 1908.

Patented June 22, 1909.

Serial'No. 431,024.

To all whom it may concern:

Be it known that I, EDWIN S. LINCOLN, citizen of the United States,residing at Brookline, in the county of Norfolk and State .ofMassachusetts, have invented certain new and useful Improvements inMultiple-Com tact Timers, of which the following is a specification'.

My invention relates to timers adapted to distribute electrical energyto the ignition systems of the cylinders of explosive engines, so as toenergize said systems and to explode the gaseous charge in the engine ormotor cylinders at the desired time.

As is well known, timers employed for the purpose above mentioned,consist essentially of a rotating member carrying a moving contactadapted to successively engage a series of stationary contacts, theengagement of the moving cont-act with any stationary contact serving tocomplete an electrical circuit by which the ignition system of thecylinder controlled by that contact is energized.

Ordinarily it is the practice to provide a series of stationary contactscorresponding in number to that of the cylinders of the enginecontrolled thereby, and mounted at angularly equal intervals on thecircumference of a stationary member axially concentric with therotating member. Thus a four cylinder timer has four stationary contactsspaced ninety degrees apart, or a six cylinder timer has six contactsspaced sixty degrees apart,

The rotating member, furthermore, has been driven so as to make onerevolution for each double revolution of the motor controlled by it, ifa four cycle motor, or for each single revolution of a two cycle motor.

The construction above outlined has led to the result, which isespecially manifest in the caseof high speed two cycle engines, that therotary member of the timer revolves with great rapidity, and inconsequence not only is there excessive wear on the timer parts, but theperiod of engagement between the contact carried by the rotating memberand the stationary contacts is of exceedingly brief duration. The saidengagement is furthermore, often imperfect, owing to the rapidity of theengagement of the contacting contacts, and to the small area of thesurthus reducing the wear on the rotating parts of the timer, and withthe further result of securing a largely increased period of engagementbetween the moving and the stationary contacts. -At the same time I aimto make provision'whereby the surface of engagement between the movingand the stationary contacts is increased to theoretically double thatpossible in a similar type of timer not embodying my invention. Theresult is a timer of greatly increased durability and efficiency ascompared with those hitherto in use.

In the drawings is shown one embodiment of my invention, Figure 1 beinga side view of the same, partly in section, and Fig. 2 a plan View ofthe same, showingcthe timer wall partly in section on the plane Bf-Z, ofFig. 1.

Referring to the drawings, 1 shows the timer base, means being provided,as screws 2 engaging curved slots 3, by which the base may beadjust-ably secured to the motor in the desired position of angularadjustment. To the base is secured the wall of the case, in dicated bythe numeral 4, the same preferably being in the form of an annular pieceof insulating material, as hard rubber or the like, andliaving thestationary contacts 5, 5 6, 6, 7, 7, and 8, 8, mounted therein. Suchcontacts may be providedwith means whereby they may be individually orcollectively adjustable, radially, or otherwise, but such means forms nopart of my invention and thereforeis not shown in the drawings. A cover9 is adapted to it over the case, being secured to the topof the walldby screws or other suitable devices.

The timer shaft which may be geared, or otherwise positively driven fromthe motor,

by means not shown in the figures, is indior electrically insulatedtherefrom, as well as.

from the timer base, as by the use of the insulating bushing 12, and thewasher 13. On

as the ,rotating member 11 revolves the contact rollers 17 roll over theinternal circumferential surface of the'wall 4.

Mounted in the wall 4,,so as tolie in the ath of the rollers 17, are aseries of contact locks 5, 5 6, 6*, 7, 7*", and 8, 8 which in number area multiple of the number of cylinders in the motor controlled thereby,being preferably twice the number of the cylinders, where th'e rotatingmember carries two contact .wheels, three times the number there arethree contact wheels, and so on.

The construction of a four cylinder timer having, as shown in thedrawings, two con-' tact rollers, and eight contacts, will alone bedescribed in illustration of my invention, the construction of timers tosuit other situations being identical in principle, and requiring onlymodification in their mechanical details. In the timer shown in thedrawings the stationary contact blocks'are spaced angularly equidistant,on the wall 4 of the timer case, and they are arranged to form four airsof diametrically o osite contacts P l P whose members are electrica lyconnected by wires or other appropriate connections. 'Thus conductor21;.electrically unites contacts 5 and 5 22 connects 6 and 6 23, 7 and7; and 24, 8 and 8 One contact of each pair of contact blocks, as forexample 5, 6, 7, and 8, are provided with binding screws or the like,bywhich may be secured wires 25, 26, 27, and 28, which .lead to one ofthe terminals of the ignition systems of the various cylinders of themotor controlled by the timer. The other terminals of the ignitionsystems of the said cylinders, maybranch from a single wire 29 leadingto binding post 16 on the cover 9 of the timer, and so be in electricalconnection with the rollers 17 through brush 15 and ring 14, or'saidterminals may be in electric connection with said rollers 17 bygrounding through the motor frame, in usual and well known manner, therotating member 11 in such case being mounted directly upon the shaft 10without the use of the insulatingbushing 12. Said rollers 17 are inelectrical connection with each other through the rotating member bywhich they are carried. When, therefore, the contact rollers 17 are inany position of engagement with the stationary contacts, as for example,with the pair of interconnected contacts 5 and 5*, the circuit leadingto the ignition system will be closed both through. the engagement ofone contact roller with contact block 5, and also through the otherroller and contact 5*. Thus an area of contacting surfaces is securedwhich is theoretically double in amount that secured in a timer of'usual construction, resulting in a largely increased efficiency for theignition system. Furthermore the symmetrical formation of the rotatingmember, incident to the use of a plurality of contact rollers, or thelike, secures a more perfect balance of the rotating member, and leadsto a smoother and more even running of the same. Again it will beobserved that, if the rotating members revolve clockwise, the contactrollers 17 will simultaneously engage contacts 6 and 6 after one eighthof a revolution of the rotating member; with contacts 7 and 7*, afterone quarter of a revolution; with contacts 8 and 8, after three eighthsof a revolution; and again coming into contact with contacts 5 and 5after one half a revolution of the rotating member has been completed.Thuslthe electrical energization of the ignition systems of all theengine or motor cylinders will be completed during one half of arevolution of the timer, and in consequence it is necessary that thetimer have a rate of revolution but half that of a timer having but asingle set of engaging contacts.

The result of the slower rate of rotation of my timer is a lessenedamount of wear, while by reason of the relatively slower speed withwhich the moving and stationary contacts engage, a more perfect contactis secured. These advantages, combined with the fact that the contactingsurfaces through which the ignition circuit is com leted, are substantially double in area t ose of a timer having but one set ofcontacting surfaces pro duce a timer of largely increased mechanicaldurability and electrical efficiency over those hitherto. employed.

Having described my invention what I claim and desire to secure byLetters Patent is:

1. In a timer ada ted to control the ignition system of mu ti-eylinderedexplosive engines, or the like, two members having a ca acity forrotation with respect to each ot er, one of said members having aplurality of contacts in electrical engagement with one terminal of theignition system of each cylinder of said engine, and the second memberembodying a plurality .of contacts arranged in electrically'insulatedsets, the number of such sets corresponding to the number of the enginecylinders control ed b the timer, and each set comprising 'a lura ity ofcontacts individually electlica y connected to each other andcollectively connected electrically to the unengaged terminal of theignition system of one of the cylinders of said engine, the contacts 01'the first member being adapted to simultaneously engage in successionwith the contacts comprised in each of the said sets as one memberrevolves 'with reference to the other member, substantially asdescribed.

2. In a timer adapted to control the ignition system of amulti-cylindered explosive engine, or the like, in combination, arotating member having a plurality of contacts, collectively inelectrical engagement with one terminal of the ignition system of eachengine cylinder, and a stationary member embodying a plurality ofelectrically insulated stationary contacts arranged in electricallyinsulated sets, the number of such sets corresponding to the number ofthe engine cylinders controlled by the timer; each set comprising aplurality of' stationary contacts, individually in electricalcommunication with each other, and collectively in electricalcommunication with the unenga ed terminal of the ignition system of oneof t 1e cylinders of said engine, the contacts of the rotating memberbeing adapted to simultaneously engage in succession with a plurality ofthe stationary contacts in each set as the rotating member revolves.

In testimony whereof I affix my signature in presence of two Witnesses.

EDWIN S. LINCOLN.

Witnesses NATHAN B. DAY, WILLIAM A. COPELAND.

